i'm getting a code 21 at throttle position sensor, i checked the voltage, and i'm getting 0 volts on the bottom wire no matter the position, and 4.33 volts closed on the middle wire and 4.73 at wot, this not good?, my car is running really rich, and it just poofs through the carb like it's backfiring, would the tps cause that?

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86 Camaro with 88 305 LB9 using 86 carb setup, edelbrock performer manifold, 305 S/R Torquer Heads, Hedman Headers, Crane Compucam 2032 edelbrock cat-back, gutted cat, slp underdrive pulley, mallory ignition, 305 h.o dual snorkel air cleaner, hypertech thermomaster chip,160 degree thermostat, 5-speed, 3.23 posi

95 Beretta Z26, 3100 V6, 4 Speed auto, stock

 

Yeah, that would cause a rich condition. Closed throttle voltage should be around .48-.5V. Tapering toward WOT, it'll stop around 4.7-5V. You want to measure the voltage off the blue wire, using black as ground. Grey is the supply voltage.

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D.R. Stevens
1984 Trans Am 305HO L69
all the usual external/free mods, original engine
1991 Firebird 305 L03
bone-dead-slow-stock